Sea State vs Boat Size (what are you comfortable with)

[black_sails]

Wasn't sure whether to post separate questions in singlehulls and multihulls but it all covers the same topic.


What kind of sea states and weather conditions (if something is somehow detached/not exactly mirroring the wind/waves/whatever for that sea state) do you feel comfortable handling not just in boats of different sizes, but of different designs? I'm pretty sure a 40 foot catamaran may have a different response than a 40 foot monohull, but if anyone has any experience with more 'exotic' hulls (HARTH, SLICE) primarily from Navy use I assume i'd love to hear about that too.


My preferred response would be opinions on different boat sizes you've been on and where it goes from Green to Yellow and Red. Green means feel totally safe, Yellow meaning feeling challenging/definately staying on your toes, Red meaning you feel unsafe (even if you have been out in those conditions, and think the boat would survive it again, you don't WANT to do it again unless you have to).

I am curious about responses all the way up to people circumnavigating and using the Drake Passage which i'm told will often have 25 foot waves and be a Sea State 10 and can get far worse than that! I'm sort of specifically interested in the conditions that would be above a normal gentle pleasure cruise - i'm specifically interested in circumnavigation, "expedition" type voyages towards the poles, and rougher than normal conditions found thousands of miles from land. My internal question is "how big of a boat would you want for blue water adventures" just in essay form preferably with personal experiences.

[FecklessDolphin]

LWL certainly makes diffe


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[FecklessDolphin]

Originally Posted by FecklessDolphin

LWL certainly makes diffe


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LWL makes a difference certainly but so does hull shape according to Marchej


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[Stu Jackson]

34 foot boat (mine) 7 ft @ 7 sec going upwind - sucked, we turned around

same boat, 9 - 14 feet at 11 seconds - delightful, 'cuz we were going downwind.

The question as written leaves too many variables.

[expatri8]

Originally Posted by Stu Jackson

The question as written leaves too many variables.

Perhaps the question is composed to let us help fill the variables,
a strategy which helps illuminate the scope of a knowledgebase.

In 10m (5m beam) workboats we found that 2m swells exceeded HSE risks
for working conditions in shallow tropical water areas for our craft and crew.
It was not dangerous to drive through, but it is nerve-wracking,
as long as we had no need to do anything involving handling deck equipment.
green 0-1.2m
yellow 1.2m-2.0m
red >2.0m
These were workboats, a sailboat is a different animal.

Our tugs and other crew boats were about 20m, and had no issue with 2m.
but at 4m these boats became just 'a ride'.
0-2m green
2m-3m yellow
4m red

note I am saying red - meaning you are okay inside, but if anything breaks
you need to go outside and fix you are in an unsafe condition.

[boatman61]

Pay me enough.. I'm comfortable.. 21ft - 64ft..

[a64pilot]

Size of the boat is one of the least relevant features that make one safe in big seas.
Difference in size between a 30' boat and a 50' boat is huge, but compared to say a 300' ship, it's insignificant, and some 300' ships are lost in storms, that some 30' sailboats survive.
Comfort wise, wave period is more important than wave size, short steep 4' waves can kick your butt, while big ole 8' rollers are hardly noticed. Of course combine big and steep or big and breaking and that's bad, real bad.

[reed1v]

Originally Posted by FecklessDolphin

LWL certainly makes diffe


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The old rule of thumb for monos was double the lwl and the boat will be 17 times as comfortable(motion range).

[Cadence]

That is one broad question!

[reed1v]

Originally Posted by Cadence

That is one broad question!

Bigger the waves, bigger the boat. Except in swells where the smaller the boat, the better the ride. Have seen freighters bashing against big ocean swells while we just bobbed up and down like ducks.

[MarkJ]

I am quite comfortable on a 2 ft swell in a 100 footer...

I remember something about half your boat size. So in a 40 footer (11m) you should be fine in 20 ft (5.5M) ocean swells I.e. long interval.

As Stu says 7 seconds is very short and 20ft seas would be untenable... and probably breaking.

Again: sail in the correct season and it's pretty difficult to hit huge seas.

Sent from a stupid phone that replaces words with weird stuff.

[estarzinger]

I can tell you that in the drake/Antarctic charter/expedition group there is a generally shared opinion that below 35' is too small for the possible conditions down there, 35-60 good for most conditions but you need to wait to avoid worst weather, and 70'+ you could go in just about anything given good seamanship.

[barnakiel]

Any small boat - relatively comfortable in fine seas but less comfortable in rough seas.

Not much to compare, you simply want the biggest boat you can handle when you think along the lines of being most comfortable in the worst seas.

We are comfortable about 10% of the passage time in our sub-30 boat.

I can't remember last time I was uncomfortable on a 70'er I sometimes help to sail.

Going North and South you not only want comfort but also maximum protection from the elements. Mess up and you get hypothermic then dead before you know it.

b.

[Cadence]

Originally Posted by reed1v

Bigger the waves, bigger the boat. Except in swells where the smaller the boat, the better the ride. Have seen freighters bashing against big ocean swells while we just bobbed up and down like ducks.

That was the broad. Height really has nothing to do with it unless period is considered and are they curling from the wind.

I'd rather be the duck. Green water over the bow does not excite me, surfing down a following sea.

[boatman61]

Originally Posted by barnakiel

Any small boat - relatively comfortable in fine seas but less comfortable in rough seas.

Not much to compare, you simply want the biggest boat you can handle when you think along the lines of being most comfortable in the worst seas.

We are comfortable about 10% of the passage time in our sub-30 boat.

I can't remember last time I was uncomfortable on a 70'er I sometimes help to sail.

Going North and South you not only want comfort but also maximum protection from the elements. Mess up and you get hypothermic then dead before you know it.

b.

On the 22ftr in a December Biscay storm I was grateful for every wave that broke over.. the warmth was wonderful..